Oil furnace



May 17, 1938, SCQTT v 2,117,511

OIL FURNACE Filed Jan. 10, 1935 w 5 Sheets-Sheet 1 May 17, 1938.

L. L. SCOTT 2,117,511

, on. FURNACE Filed Jan. 10, 1935 5 Sheets-Sheet 2 do N,

May 17, 1938. SCOTT 2,117,511

OIL FURNACE Filed Jan. 10, 1935 3 Sheets-Sheet 3 Patented May 17, 1938 UNITED STATES PATENT OFFICE 3 Claims.

This invention relates to a novel construction of an oil furnace used for heating homes and the like. One of the objects of my invention is to provide a simple and relatively inexpensive oil furnace that will be durable and reliable in oper ation.

Another object of my invention is to provide a novel arrangement for burning the oil in said furnace so as to get very high combustion efficiency as well as over-all furnace efliciency.

A further object is to provide an oil furnace that will get up steam or raise the temperature of water very rapidly, and that will have very rapid circulation.

further object is to provide what I term as an economizer section, which section is lined with a sound absorbing material as well as a heat insulating material so as to absorb to a large extent the noise of combustion.

In the accompanying drawings, Figure 1 is a sectional view of my oil furnace, showing the burner located underneath, and arranged to burn a vertical oil flame.

Figure 2 is a front view of Figure 1 with a part of the boiler case broken away.

Figure 3 is a sectional plan View of Figure 2, the section being taken on the line AA of Figure 2.

Figure 4 is a sectional view of the preferred form of my oil furnace, similar to Figure 1, but with the burner and outer casing removed.

Figure 5 is a plan sectional view on the line BB of Figure 4.

Referring now to the drawings, the numeral I indicates an oil burner which is provided with a motor 2, and an air blower 3. The numeral 4 indicates an ignition transformer adapted to furnish a spark at the spark terminals 5, which spark is adapted to ignite the oil sprayed from the nozzle 6. The motor 2 is adapted to drive an oil pump '1 (see Figure 2), which pump is adapted to supply oil from the tank not shown, and deliver it to the spray nozzle 5, said motor is also adapted to drive the blower wheel in blower 3, and to deliver air through the vertical air tube 8 to promote combustion of the oil from the spray nozzle 6. The type of burner here illustrated and described is more fully disclosed in my Patent No. 1,334,566. The air is supplied under low pressure of water, about) and is insufiicient to cause any substantial atomization of the oil. This burner is to be distinguished from others which use air under relatively high pressure for the purpose of atomization. In the present structure the oil sprayed by the nozzle 6 and thereby mixed with the air has little kinetic energy and can only travel a limited distance upwards. It will either be burned or fall back into the flame, and will not strike the crown sheet or water legs of the boiler, which, in the embodiment specifically illustrated, form parts of the walls of the combustion chamber. It is thus to be distinguished from burners of the other type mentioned in which the kinetic energy of the air and oil mixture is considerable and in the environment here disclosed, is sufficient to carry some of the oil beyond the flame into contact with the cooler portions where the oil will collect thereby prevening proper and complete combustion.

The numeral 5 indicates fire brick lining for the combustion chamber, which is substantially square. The combustion chamber is surrounded by the water section of the boiler II], which section connects to the upper water section H. The numeral l2 indicates the outlet for steam or hot water, and the numeral [3 indicates the return pipe connections which connect to the lower part of the boiler. The numeral I4 indicates a copper coil commonly used for heating domestic hot water. The numeral l5 indicates a gauge commonly used, and the numeral I6 indicates a steam blow-off valve commonly used on this class of equipment. The numeral ii indicates an access door in the outer casing l8 for observing the oil flame through the peep-hole I9, which peep-hole is usually covered by pyrex glass. The numeral 20 indicates insulation which completely covers the entire boiler, with the exception of the bottom. The numeral 2| indicates a sound absorbing blanket which is secured to the inside lower part of the boiler casing l 8 around the oil burner. This material will absorb mechanical noises from the burner. It will be noted in the structure shown in Figures 1, 2 and 3 that water tubes are arranged to join the lower water section with the top water section, where in the structure shown in Figures 4 and 5 there is a steel box-like water compartment around the fire brick 9. Combustion of the oil fire is completed in the combustion chamber which is surrounded by the fire brick 9. The products of combustion pass to the economizer space 22 through the opening 23, said products of combustion acting to heat the economizer 24, which is located in the economizer space 22 and connected to the upper and lower sections of the boiler. The products of combustion pass downward in the economizer space 22 and out through the flue opening 25 to the chimney not shown. The numeral 26 (see Figure 1) indicates a safety device commonly used with oil burners, but which forms no part of the present invention. It will be noted that the economizer 24 in Figures 4 and consists of six copper coils which are secured to the top and bottom of the boiler proper by union connections 21. These coils are wound right and left hand, and the three coils nearest to the boiler are the left hand coils. The reason for winding them right and left hand is for convenience in making connections to the boiler without having the front row of coils interfere with the back row of coils. The numeral 28 (see Figures 4 and 5) indicates a sound absorbing material as well as a heat insulator which entirely surrounds the economizer coils 24. The numeral 29 indicates a cast iron door having insulating material attached to its under side which covers an opening at the upper part of the economizer housing 22 and this opening serves as a pressure relief door in the event of an explosion of vaporized oil within the boiler and also serves as an access door for cleaning the economizer 2 2. An access door 35 (see Figure 1) is provided in the casing and acts as a cover for the opening through which the door 29 is removed.

In the structure shown in Figures 1, 2 and 3, where water tubes join the top and bottom sections, I provide tie bolts 3| for holding the top and bottom sections together. The springs 32 are provided to allow for the difierence in expansion and contraction between the vertical water tubes and the bolts 3|. The numeral 33 (see Figure 2) indicates the conventional water glass and gauge cocks commonly used on steam boilers. The numeral 34 (see Figures 4 and 5) indicates support brackets for attaching the flue casting 25. These brackets are rigidly secured to the boiler proper. The numeral 35 indicates support legs for supporting the boiler proper, and the numerals 36 and 31 (see Figure 2) indicate removable panels for giving access to the oil burner I. The numeral 38 (see Figure 2) indicates louver openings in the sides of the casing l8 through which air passes to the burner I. It Will be noted that there is a space 39 between the casing l8 and the boiler insulation 20.

I have found that by projecting atomized oil from the spray nozzle vertically and by providing an enclosed combustion chamber which is surrounded by a heat absorbing medium I get unusually high combustion efficiency. The reason for this is that a small particle of atomized oil which is projected from the nozzle has very little kinetic energy and can only travel a limited distance upwards where it must either burn or fall back into the flame. Where the atomized oil is projected horizontally as is common practice this same result cannot be obtained and some of the oil particles escape to the chimney unburned, thereby making for low combustion efificiency.

It will be noted that I have provided a U shaped travel for the products of combustion, namely, upward, over and downward to the flue. By this arrangement the products of combustion are entirely surrounded by heat absorbing medium and said products of combustion pass to the flue at the point where the coolest Water enters the economizer section, thereby making for high efiiciency in the heat absorbing medium.

I claim:-

1. In a boiler, an oil burner having a nozzle arranged and adapted to spray oil vertically, vertical walls of refractory material spaced from the axis of the nozzle and extending upwardly from the level of the nozzle a sufficient distance to surround the space of active combustion and forming a combustion compartment, a Water shell over the compartment, a Water shell near the bottom of the compartment, one or more water legs about the compartment connecting the shells, an economizer chest parallel to said compartment and communicating at its top with the top of the compartment, a flue outlet from the chest, and Water tubes in the chest connected between said shells.

2. In a boiler, a combustion compartment, a water container over and above said compartment, a casing having sound absorbing walls about the top and sides of the boiler, an oil burner tube opening into the combustion compartment, and a sound absorbing blanket about said tube adjacent the compartment.

3. In a boiler, a vertical combustion compartment, a water container over and about said compartment, a casing having sound absorbing walls about the top and sides of the boiler, legs for supporting the boiler above a floor upon which it is placed, an oil burner tube opening into the combustion compartment, and a sound absorbing blanket about said tube immediately below the compartment.

LEWIS L. SCOTT. 

